Methods For Producing Metal Powders And Metal Masterbatches

ABSTRACT

A method for producing a metal powder that combines molten reducing metal and metal halide in a space that is substantially free of oxygen and water, wherein the molten reducing metal is sodium and/or potassium, or aluminum (or magnesium or titanium) and is present in a stoichiometric excess to the metal halide which is a solid or liquid, thereby producing metal particles and salt, removing unreacted reducing metal, optionally removing the salt, and recovering the metal powder, is described. A method for producing a metal masterbatch wherein the molten reducing metal is aluminum, magnesium, and/or titanium and after combining molten aluminum (or magnesium or titanium) and metal halide in the reaction space, substantially removing the produced metal salt to obtain the metal masterbatch which comprises at least a portion of the molten aluminum (or magnesium or titanium) and at least one metal also is described.

This application claims the benefit under 35 U.S.C. §119(e) of priorU.S. Provisional Patent Application No. 62/374,212, filed Aug. 12, 2016,which is incorporated in its entirety by reference herein.

BACKGROUND OF THE INVENTION

The present invention relates to methods for producing metal powders,salt-coated metal powders, and metal masterbatches.

Metal powders can be used for advanced metallurgical processes, such asnear net shape powder pressing, and additive manufacturing, includinglaser metal deposition (LMD), direct metal laser sintering (DMLS),selective laser sintering (SLS), and selective laser melting (SLM). Theend products find applications in a wide variety of industries,including aerospace, medical, and electronics. Other applicationsinclude the production of wire bar stock for rolling into medical alloys(e.g., superconducting wires for MRI machines), sputtering targets inelectronics manufacturing for thin film metal deposition in displays,use in semiconductors and data storage devices, superalloy production,intermetallic powders for the manufacture of jet engine components, andphotovoltaic cells. Metal powders can also be pressed into dense objectsusing conventional pressing techniques. Salt-coated metal powders can beused for particle strengthening of metals.

Preferably, metal powders are highly pure and have consistent flowproperties. However, processes for achieving metal powders having suchcharacteristics require further development. Accordingly, there is aneed in the art for methods of making pure metal powders that haveadequate flow properties such that the powders can be used for advancedmanufacturing applications.

SUMMARY OF THE INVENTION

A feature of the present invention is to provide a process for producinghigh purity, low oxygen content metal powders with good flow properties.

A further feature of the present invention is to provide a method forproducing a metal masterbatch that comprises unreacted aluminum reducingmetal and at least one other metal formed from a reaction of thealuminum metal and a metal halide.

A further feature of the present invention is to provide a method forproducing a metal masterbatch that comprises unreacted magnesiumreducing metal and at least one other metal formed from a reaction ofthe magnesium metal and a metal halide.

A further feature of the present invention is to provide a method forproducing a metal masterbatch that comprises unreacted titanium reducingmetal and at least one other metal formed from a reaction of thetitanium metal and a metal halide.

Additional features and advantages of the present invention will be setforth in part in the description that follows, and in part will beapparent from the description, or may be learned by practice of thepresent invention. The objectives and other advantages of the presentinvention will be realized and attained by means of the elements andcombinations particularly pointed out in the description and appendedclaims.

To achieve these and other advantages, and in accordance with thepurposes of the present invention, as embodied and broadly describedherein, the present invention relates to a method for producing a metalpowder. The method includes: a) combining at least one metal halide andat least one molten reducing metal in a space that is substantially freeof oxygen and water to obtain a reaction product that includes at leastone metal salt and metal; b) substantially removing the molten reducingmetal in the reaction product; c) recovering at least the metal, andoptionally the at least one metal salt. The molten reducing metal ispresent in a stoichiometric excess to the metal halide. The moltenreducing metal can be primarily 1) sodium and/or potassium or 2)aluminum, or magnesium, or titanium. The at least one metal halide is asolid or liquid, with the proviso that the molten reducing metal isdifferent from the metal of the at least one metal halide. In thereaction product, the metal of the metal salt is the molten reducingmetal, and the ‘metal’ recovered from the reaction product is from themetal of the metal halide.

The present invention further relates to a method for producing a metalmasterbatch. The method includes: a) combining at least one metal halideand at least one molten reducing metal in a space that is substantiallyfree of oxygen and water to obtain a reaction product that comprises atleast one metal salt and metal; b) substantially removing the at leastone metal salt to obtain the metal masterbatch comprising at least aportion of the molten reducing metal, and at least one other metal. Stepb) can occur as the reaction product forms and/or after the reactionproduct forms. The molten reducing metal is present in a stoichiometricexcess to the metal halide. The molten reducing metal can be orprimarily be aluminum or an alloy thereof, magnesium or an alloythereof, or titanium or an alloy thereof. The at least one metal halideis a solid or liquid, with the proviso that the molten reducing metal isdifferent from the metal of the at least one metal halide. The metal ofthe metal salt is the molten reducing metal, and the ‘other metal’recovered from the reaction product is from the metal of the metalhalide.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide a further explanation of the presentinvention, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this application, illustrate some of the features of the presentinvention and together with the description, serve to explain theprinciples of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process flow chart describing a method according to anexample of the present application.

FIG. 2 is a process flow diagram describing a method according to anexample of the present application.

FIG. 3 is a process flow diagram describing a method according to anexample of the present application.

FIG. 4 is a process flow diagram describing a method according to anexample of the present application.

FIG. 5 is a process flow diagram describing a method according to anexample of the present application.

FIG. 6 is a schematic illustration of a suitable bake out vessel for aprocess according to an example of the present application.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to methods of producing metal powdersand/or metal masterbatches that incorporate metal halide reductionreactions. These processes can yield high purity and/or low oxygencontent products. These methods can be practiced in continuous,semi-continuous, or batch arrangements. As an option, methods can bepracticed as a continuous process with recycling of excess reactant. Theterm “metal powders” can refer to metallic primary particles,aggregates, agglomerates, other discrete metal particles, or anycombination thereof. The term “masterbatch” can refer to a physicalmixture comprised predominantly of two or more different kinds of metals(e.g. in elemental form), wherein the mixed metals retain their ownrespective chemical properties and have not chemically reacted with eachother. The masterbatch optionally can be or include a metal alloy, anintermetallic compound, metal carbide, metal nitride, metal boride,metal silicide, metal aluminide, or any combination thereof, or othermetal compounds (e.g., one or more ceramics) in the alternative or inaddition to the indicated physical mixture of different elementalmetals.

Metal powders can be formed in a method of the present invention byreducing a solid or liquid metal halide with a molten reducing metal ina sealed reaction vessel that is substantially free of oxygen and water(e.g., below 100 ppm oxygen and below 100 ppm water), wherein the moltenreducing metal is present in a stoichiometric excess to the metalhalide. Metal powders and a metal salt can be produced, which areseparated from the unreacted molten reducing metal. As an option, themetal powder can be separated from the metal salt (e.g., from 95 wt % to100 wt % of the total metal powder present can be separated from themetal salt).

In the present invention, the molten reducing metal means that thereducing metal is present as a liquid and not a vapor or a solid. Forpurposes of the present invention, as an option, minor amounts, such asbelow 5 wt %, below 2.5 wt %, below 1 wt %, below 0.5 wt %, below 0.25wt %, below 0.1 wt %, below 0.05 wt %, below 0.01 wt % or below 0.001 wt% or zero wt % (based on the total weight of the reducing metal present)can be optionally present in a state other than a liquid or moltenstate.

In the present invention, the molten reducing metal can comprise,consists essentially of, or consists of, or include either 1) potassiummetal or sodium metal or a combination of potassium metal and sodiummetal (e.g., an alloy of sodium and potassium), or 2) aluminum metal oralloy thereof, or magnesium metal or alloy thereof, or titanium metal oralloy thereof. For option 1), the molten reducing metal can comprise atleast 90 wt % sodium metal, at least 90 wt % potassium metal, or atleast 90 wt % of a combination or mixture or alloy of potassium metaland sodium metal. This percent of at least 90 wt % in each instance canbe at least 95 wt %, at least 99 wt %, at least 99.5 wt %, at least 99.9wt %, or 100 wt % such as from 90 wt % to 100 wt %, or from 95 wt % to100 wt % (all based on the total weight of the molten reducing metal).When the amount of molten reducing metal for potassium and/or sodium isless than 100 wt % but at least 90 wt %, the remaining amount can be, orinclude for instance other metals in a molten state, such as calciumand/or magnesium and/or one or more other metals, and/or can be one ormore oxides. For option 2), the molten reducing metal can comprise atleast 90 wt % aluminum metal, or magnesium metal or titanium metal, suchas at least 95 wt %, at least 99 wt %, at least 99.5 wt %, at least 99.9wt %, or 100 wt % such as from 90 wt % to 100 wt %, or from 95 wt % to100 wt % (all based on the total weight of the molten reducing metal).For purposes of the present invention, the ‘aluminum metal’ can be orinclude one or more aluminum alloys. These aluminum alloys typicallyhave about 90 wt % or more of aluminum in the alloy based on the totalweight of the alloy. For purposes of the present invention, the‘magnesium metal’ can be or include one or more magnesium alloys. Thesemagnesium alloys typically have about 90 wt % or more of magnesium inthe alloy based on the total weight of the alloy. For purposes of thepresent invention, the ‘titanium metal’ can be or include one or moretitanium alloys. These titanium alloys typically have about 90 wt % ormore of titanium in the alloy based on the total weight of the alloy.For purposes of the present invention, for either option or anyembodiment of the present invention, these percentages for potassium,sodium, aluminum, magnesium, and titanium are based total weight of thecomponents or materials only in the molten state and not in any otherstate. Also, for purposes of the present invention, unless statedotherwise, reference to “potassium” or “sodium” or “aluminum” or“magnesium” or “titanium” means the above weight percents or purities asprovided here. An alloy is a mixture of metals or a mixture of a metaland another element. Alloys are defined by a metallic bonding character.An alloy may be a solid solution of metal elements (a single phase) or amixture of metallic phases (two or more solutions). In the case ofaluminum alloy, the predominate element is aluminum. In the case ofmagnesium alloy, the predominate element is magnesium. In the case oftitanium alloy, the predominate element is titanium. Preferredpercentages are provided above.

In the methods of the present invention, the at least one metal halidecan be, include, consists, of or comprises Ti halide, V halide, Crhalide, Mn halide, Fe halide, Co halide, Ni halide, Cu halide, Znhalide, Ga halide, Ge halide, As halide, Se halide, Zr halide, Nbhalide, Mo halide, Ru halide, Rh halide, Pd halide, Ag halide, Cdhalide, In halide, Sn halide, Sb halide, C halide, Si halide, Te halide,Hf halide, Ta halide, W halide, Hg halide, Tl halide, Pb halide, or Bihalide or any combination thereof. The halide can be chloride, bromideor iodide. Any of the halides in this list can be or exclusively be achloride (in other words, one or more metal chlorides).

As stated, in the present invention, for the various methods andreactions described herein, the metal of the formed metal salt is (from)the molten reducing metal (e.g., Na, K, or Al, Mg, Ti), and the ‘metal’recovered from the reaction product is from the metal of the metalhalide (e.g, Ti, V, Ta, Nb, Sn, Si, Zr, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn,C, Si, Ga, Ge, As, Se, Mo, Ru, Rh, Pd, Ag, Cd, In, Sb, Te, Hf, W, Hg,Ti, Pb, Bi, and the like), or a ceramic thereof, or a nitride thereof,or a boride thereof, or a carbide thereof. Two or more halides can beused. When two or more metal halides are used, one metal halide isreactive and the second metal halide can be reactive or non-reactivewith the molten reducing metal. When two or more metal halides are used(e.g, two metal halides, three metal halides or more), each of themetals of the metal halide, if reactive, can result in obtaining a metalalloy of these metals or an intermetallic compound of these metals. If anon-reactive metal halide is present, the metal of the metal halide willnot be part of the resulting metal. A non-reactive metal halide, ifpresent, for instance, can be used as an additive, forming a complexhalide salt, to lower the melting point of the reactive metal halide, orto reduce the vapor pressure of the reactive metal halide, or to formliquid mixtures or solutions with other metal halides. For instance,NaCl (non-reactive metal halide) can be used with a reactive metalhalide (AlCl₃). The mol % of the non-reactive metal halide to reactivehalide can be from 1:99 to 99:1, and preferably is 20:80 to 80:20, or40:60 to 60:40, or from 50 mol % to 65 mol % of the non-reactive metalhalide to 60 mol % to 35 mol % of the reactive metal halide. A phasediagram of the two metal halides can provide preferred mol % ratios toachieve the desired lower melting point. When two or more halides areused, they can be added as a mixture or separately or at differenttimes. When a non-reactive metal halide is used with a reactive metalhalide, the two should be added as a mixture and can be added as aliquid or solid. When two or more metal halides are used, at least oneis a solid or liquid, but the other metal halide can be a vapor, liquid,or solid.

As an option, in the present invention, the metal salt formed in any ofthe processes of the present invention can form a partial or completecoating around the metal that is formed in the reaction product. Asdescribed herein, the metal that is formed can be present as a metalpowder and be present as primary particles, agglomerates, aggregates,briquettes and the like. The metal salt coating can be any thicknessaround the metal formed (e.g, around the metal powder), for instance,from about 1 nm to about 100 nm or more, such as from about 100 nm toabout 5 μm or from about 500 nm to about 10 μm or thicknesses above orbelow any of these ranges. The salt coating can be removed by any saltremoving technique such as an aqueous washing or sublimation and thelike.

The term “substantially free of oxygen and water” as used herein meansthat any content of oxygen or water present during the combining of thereducing metal and metal halide is insufficient to prevent the metalpowder product from having the purity described herein. For instance,the purity (e.g., by wt %) of the finished metal powder can be 95% metalor greater, or 99% metal or greater such as from about 99.5% metal orgreater and more preferably 99.95% metal or greater and even morepreferably 99.99% metal or greater, or 99.995% metal or greater or99.999% metal or greater, wherein the metal refers to the metal of themetal halide reactant and not the reducing metal or other source ofmetal. The metal powders produced by the methods described herein can behighly pure. In particular, the metal powders can have a minimal amountof oxygen bonded to the metal. Reducing the quantity of oxygen bonded tothe metal powder has been technically challenging in the art, and thusimprovements in metal powder purity represent a substantial technicalimprovement. The reaction vessel that is substantially free of oxygenand water can be filled or purged with an inert gas, preferably argon,prior to or while maintaining the molten reducing metal in the sealedreaction vessel.

In methods of the present invention, at least one metal halide can bereacted with a stoichiometric excess of a reducing metal. The term“stoichiometric excess” means the molar amount of the molten reducingmetal present in the reaction zone is in excess based upon the amount ofmetal halide present and available to react therewith. The moltenreducing metal can be in at least a 5:1 stoichiometric excess to themetal halide, though in some cases it can be less than a 5:1stoichiometric excess. In other cases, it can be more than a 5:1stoichiometric excess, such as at least a 10:1 stoichiometric excess, orother values.

When a solid metal halide is used in the method of the presentinvention, the reducing metal is heated to a temperature above itsmelting point and below its boiling point to provide a molten materialwhich can be split into a stream that is passed through a cooler toprovide a cooled stream that has a temperature that is still above themelting point of the reducing metal and below a reaction temperature ofthe reducing metal with respect to metal halide, and another stream thatis passed through a heater to provide a (further) heated stream of thereducing metal. The split can be from 10:90 to 90:10 by volume (cooledstream:heated stream), or from 20:80 to 80:20, or from 40:60 to 60:40and the like. The cooled stream of reducing metal is combined with solidmetal halide, such as metal halide in powder form, to disperse the metalhalide therein to form a mixture (e.g., a slurry). As an option, theheated stream of reducing metal can be heated to a temperature such thatwhen its mass is combined with the mass of the mixture of solid metalhalide and cooled reducing metal, the resulting combination has atemperature at or above a reaction temperature of the reducing metalwith respect to metal halide. As an option, additional heating can beprovided before the combination reaches the reaction zone or, at thereaction zone, or both locations, to provide a reaction temperature. Theheated stream of reducing metal and the mixture of cooled reducing metaland solid metal halide can be combined, such as in an eductor, andpassed through a reaction zone with the molten reducing metal present instoichiometric excess to the metal halide to produce a metal reactionproduct. As indicated, additional heating of the reducing metal andmetal halide materials can be provided before and/or in the reactionzone to raise the temperature of the mixture to a reaction temperature,or maintain the materials at a reaction temperature, or both. The spacewhere the metal halide and molten reducing metal are contacting at areaction temperature, such as the reaction zone, and/or may be in theeductor, preferably are maintained to be substantially free of oxygenand water. The metal reaction product and remaining molten reducingmetal can be collected from the reaction zone in a settling and bake outvessel. The remaining (unreacted) molten reducing metal in the reactionproduct can be substantially removed, such as by pouring or siphoning orother separation method. Metal salt and the metal reaction products thatremain in the vessel can be recovered, and the metal reaction productcan be separated from the metal salt.

When a liquid metal halide is used in the method, the reducing metal canbe passed through a heater to provide a heated liquid stream, such asdescribed hereinabove, that can provide a reaction temperature withrespect to metal halide when the heated reducing metal and metal halideare combined, and without the reducing metal being split into differentstreams for separate cooling and heating. Liquid metal halide isintroduced into the heated stream of reducing metal, such as byinjection, and the resulting mixture of heated reducing metal and liquidmetal halide are passed through a reaction zone with the molten reducingmetal present in stoichiometric excess to the metal halide to produce ametal reaction product. The space, such as the reaction zone, or whichmay be the flow passageway connecting the location of liquid metalhalide introduction and the reaction zone, where the metal halide andmolten reducing metal are contacting at a reaction temperature, can bemaintained to be substantially free of oxygen and water as previouslydescribed. The metal reaction product and remaining molten reducingmetal can be collected from the reaction zone in a settling and bake outvessel, and the remaining molten reducing metal in the reaction productcan be substantially removed, and the metal salt and the metal reactionproducts that remain can be recovered, and the metal reaction productcan be separated from the metal salt, as previously described.

In general, when the molten reducing metal is sodium and/or potassium,once the reaction product is formed and is present with the excess orunreacted molten reducing metal, at least a portion of the excess orunreacted molten reducing metal (e.g., from 10 wt % to 100 wt %, or from25 wt % to 99.5 wt %, or from 50 wt % to 99 wt %, or from 75 wt % to 99wt %, or from 85 wt % to 99 wt %, or from 95 wt % to 99.5 wt % by weightof the excess or unreacted molten reducing metal) can be separated fromthe reaction product (e.g., the metal formed and the metal salt) bycausing a phase separation between the excess or unreacted moltenreducing metal and the metal and metal salt. Generally in such aprocess, and if the temperature of the molten reducing metal and metaland metal salt are high enough, the excess or unreacted molten metalwill phase separate (liquid phase separation) and generally is on topwith the other phase of metal and metal salt at the bottom. This permitseasy separation of the two phases by various techniques, such asdecanting, siphoning, and the like. This generally occurs when theoverall mixture is at a temperature above the melting point of the metalsalt present. For instance, when the metal salt is NaCl, a temperatureabove 801° C. is used to achieve phase separation. Then as stated, theremaining amount of molten reducing metal can be removed by the varioustechniques described herein.

In general, when the molten reducing metal is aluminum (or alloythereof), magnesium (or alloy thereof) or titanium (or alloy thereof)phase separation is not used and generally it is preferred to keep theexcess or unused aluminum (or magnesium or titanium) present and toinstead remove the metal salt of the reaction product by heating thereaction product and excess or unused aluminum (or magnesium ortitanium) to a temperature that causes vaporization of the metal salt.This vaporization and removal can occur as the reaction product formsand/or after formation of the reaction product. Any amount of the metalsalt can be removed this way, such as from about 10 wt % to 100 wt %, orfrom 25 wt % to 99.5 wt %, or from 50 wt % to 99 wt %, or from 75 wt %to 99 wt %, or from 85 wt % to 99 wt %, or from 95 wt % to 99.5 wt % byweight of the metal salt present.

The metal powders produced by the methods described herein can have asmall particle size, and/or narrow particle size distribution, and/orimproved flow characteristics, or any combinations of these, which canbe determined using a Hall flow meter according to standardized testingprocedures, such as ASTM B213. The methods described herein can produceprimary particles having a size ranging from about 5 to about 250nanometers, or from about 25 to about 200 nanometers, or from about 50to about 175 micrometers, or from about 75 to about 150 micrometers, orother sizes. The primary particles can form aggregates having anaggregate size of from about 1 to about 250 microns in diameter, fromabout 25 to about 200 nanometers, or from about 50 to about 175micrometers, or from about 75 to about 150 micrometers, or other sizes.Particle size can be determined by scanning electron microscopy (SEM)imaging. The particle sizes indicated in this respect can refer toaverage size, D50 size, or D90 size. Electron microscopy works bybombarding a sample with a stream of electrons and monitoring either theresulting scattering (SEM) effects. These electrons are detected andconverted into magnified images of particles in the sample dispersion.Image analysis software uses this information to generate particle sizedata for individual particles, number based size distributions for theentire dispersion and various shape and morphological parameters. SEMcan produce accurate 3D images of particles.

Three variables can exhibit a high degree of influence on powderparticle size: the temperature at which the reaction occurs, therelative concentration of the metal halide to the concentration of thereducing metal, and the melting point of the produced metal or alloypowder. Typically, the metal powder particle size is proportional tothese variables according to Formula (1), where T is the temperature inKelvin:

$\begin{matrix}{{Metal}\mspace{14mu} {Powder}\mspace{14mu} {Particle}\mspace{14mu} {Size}\mspace{14mu} {\alpha \left\lbrack \frac{\left\lbrack {{Concentration}\mspace{14mu} {of}\mspace{14mu} {Metal}\mspace{14mu} {Halide}} \right\rbrack}{\left\lbrack {{Concentration}\mspace{14mu} {of}\mspace{14mu} {Reducing}\mspace{14mu} {Metal}} \right\rbrack} \right\rbrack}T^{\frac{1}{3}}} & (1)\end{matrix}$

In view of the Formula (1), reaction conditions that favor theproduction of smaller particles include a lower temperature and a lowconcentration of metal halide relative to the concentration of thereducing metal. Without wishing to be bound by theory, the process ofparticle and aggregate formation parallels standard particle flamesynthesis processes. Thus, when a primary particle or cluster encountersanother cluster, they stick together to form an aggregate that tends tohave an open structure, provided the conditions (temperature andparticle density) permit continued aggregation. Thus, smaller aggregatesare produced when the concentration of the metal halide is lower becausethe metal powder particles that form are more dispersed in the reducingmetal, and therefore the metal powder particles are less likely tophysically interact and form aggregates. Finally, the particles arelarge and cool enough that the aggregates freeze. Additionally, athigher temperatures the particles are stickier so they coalesce forlonger. Therefore, the primary particles are larger and have a smallersurface area. At higher concentrations, the particles can collide andcoalesce more rapidly before they cool, again leading to larger primaryparticles and lower surface area.

A method for producing a metal masterbatch is provided that uses a metalhalide reduction reaction as part of the process. With aluminum or analloy thereof used as a reducing metal (in the weight percent amountsindicated earlier) for combining with a solid or liquid metal halide(s)as described herein, the reaction product metal and a salt can beproduced in the reaction zone and collected with excess reducing metalin a separate vessel or tank, wherein the salt, and not the excessreducing metal, is separated out, so as to obtain a metal masterbatchcomprising at least a portion of the reducing metal and reaction productmetal. The reaction product metal can be, depending on the number ofdifferent starting metal halides used and types, a metal, a metal alloy,an intermetallic (intermetallic compound), or a ceramic (boride orcarbide). For instance, if AlCl₃ and carbon tetrachloride are used asthe two starting metal halides, the resulting metal can be an aluminumcarbide. If the metal halides used are TiCl₄ and SiCl₄, the resultingmetal can be a Ti—Si alloy or intermetallic, and so on. Aluminumtrichloride, for instance, sublimates at about 180° C. at one atmospherepressure, so it can be selectively volatized and removed from excessaluminum and the metal formed from the metal halide reduction reactionwhich have a higher boiling points. Other aluminum halides withcomparable sublimation or vaporization temperatures with respect toaluminum and reaction product metal can be selectively removed in asimilar manner.

Another advantage of the methods described herein is that they canreduce the amount of corrosion that occurs. For example, previous gasphase reactions typically offer a lower reaction throughput, and theycan also yield substantial corrosion because of the increase in thereaction rate for chloride corrosion processes at elevated temperatures.The methods of the present invention can avoid or have reduced risk ofthese drawbacks and disadvantages.

As described herein, reacting a metal halide with a molten reducingmetal using split flow of heated and cooled streams of molten reducingmetal for solid metal halide processing, or injection of liquid metalhalide, can yield particles that are highly pure and provide improvedflow properties. Preferably, the reactions occur under conditions thatremain constant or bounded by a limited range of temperatures andstoichiometry. The methods described herein typically involve steps thatare shown in FIG. 1.

The overall process, indicated as 100 in FIG. 1, has severalalternatives, including with respect to whether a solid or liquid metalhalide is used, whether a metal powder product or a masterbatch productis desired, and other alternatives and options indicated herein. First,molten reducing metal (as described herein), such as 1) sodium,potassium or both, or 2) aluminum or magnesium or titanium, is provided101. These metals are used for illustration, and other reducing metalsmay be used. Sodium has a melting point of about 98° C., and aluminumhas a melting temperature of about 660° C. Alternative A in the processshown in FIG. 1 is for solid metal halide processing, and alternative Bis for liquid metal halide processing. In alternative A, the moltenreducing metal is split into two streams (102), wherein a portion of thereducing metal is cooled below a reaction temperature of the metalhalide (103A) and the remaining portion is heated to a reactiontemperature with metal halide (103B). The cooled stream of reducingmetal is fed to an area (e.g., funnel) where solid metal halide isadded, such as gravity fed as a dry flowable powder, to the flow ofreducing metal through the funnel (104). The metal halide powdercombines with the cooled reducing metal, and can form a slurry. Theslurry from step 104 and the heated reducing metal are combined in amixing/dispersing device (105), such as in an eductor. The resultingmixture or dispersion is fed to a reaction zone (106), such as a pipe,mixing tank with an agitator forming a vortex, or other reaction zonearrangement. The metal halide can be reduced by the reducing metal toproduce metal particles. In alternative B, the molten reducing metal isheated (122) with no split stream for cooling. Liquid metal halide isinjected or otherwise introduced into the heated molten reducing metal(123), and the resulting combination is fed to the reaction zone (106).After the reaction in the reaction zone for either alternative A or B,the remaining, unreacted reducing metal can be removed from the metalparticles in a settling/bake out tank (107). The removed excess reducingmetal can be recycled by filtering and cooling it for reuse (108). Inthis option, the salt byproduct then can be removed, and the metalpowder particles are recovered (not shown). As shown in FIG. 1, anothermethod of the present invention is the formation of a masterbatch, suchas using aluminum reducing metal (or magnesium or titanium), wherein thereaction products and excess (unreacted) reducing aluminum metal (ormagnesium metal or titanium metal) from the reaction zone (106) are fedto a volatization/masterbatch formation tank where aluminum saltreaction (or magnesium salt reaction or titanium salt reaction)by-product of the reduction reaction is removed, such as byheat-volatization (124) alone or in combination with other salt removaltechniques, to leave unreacted aluminum (or magnesium or titanium) andreaction product metal in the tank as a masterbatch material. For thecase of making a masterbatch in “magnesium” or “titanium,” the resultingmagnesium or titanium salt is removed as either a slag from the surfaceof the reducing metal or is heat-volatilized.

Examples of process and equipment arrangements that can be used toperform these process flow options are shown in FIGS. 2, 3, 4, and 5.

In FIG. 2, a method for making a metal powder of the present invention,indicated as 200, is shown which includes use of a solid metal halide207 and a storage tank 201 of molten reducing metal (e.g., 1) Na and/orK, or 2) Al, Mg, or Ti). The reducing metal is introduced instoichiometric excess with respect to the metal halide in this method,such as in a range described herein. The sodium and/or potassiumreducing metal or aluminum reducing metal (or magnesium reducing metalor titanium reducing metal) is pumped through a continuous loop 214using pump 202, such as an electromagnetic pump (EM pump). Anelectromagnetic pump is a pump that moves ionizable liquid metal usingelectromagnetism. An electromagnetic pump can have no moving mechanicalparts which can be corroded by heated reducing metal. A cold trap 203installed on the loop 214 is used to remove contaminants prior tostarting up production. Once the contaminants are removed, the cold trapcan be valved off until needed again. The electromagnetic pump 202 pumpsthe molten sodium and/or potassium or molten aluminum (or moltenmagnesium or molten titanium) to a flow split 204. As an option, morethan a predominant (>50%) amount, or from 51% to 95%, or from 60% to90%, or from 65% to 85%, or other amounts of the mass flow of the moltenreducing metal arriving at split 204 is directed into the stream feedingthe heater 208, and a minority amount (<50%), or from 49% to 5%, or from40% to 10%, or from 35% to 15%, or other amounts is directed to thecooler 205. As an option, the flow to the cooler 205 can be from about 1to about 7 gallons/min (GPM), or from about 2 to about 6 GPM, or about 3GPM, or other values, and the flow to the heater 208 can be from about11 to about 19 GPM, or from about 13 to about 18 GPM, or about 17 GPM,or other values. The split flows can be controlled using valves andCoriolis flow meters (not shown).

The cold sodium and/or potassium stream can be directed to flow around afunnel 206. Metal halide powder, as a solid form of metal halide, can beadded to this funnel. The sodium and/or potassium, or the aluminum (ormagnesium or titanium) flows around the funnel 206 and can collect themetal halide powder and the resulting mixture or slurry can be drawnthrough an eductor 209. The eductor 209 can use the hot sodium and/orpotassium, or the hot aluminum (or magnesium or titanium) flow as themotive fluid sucking the metal halide slurry into it. The additionalheat provided by the hot sodium and/or potassium stream (or the aluminumor magnesium or titanium stream) can initiate the reduction reaction.The reaction can occur in a reaction zone 210. The reaction zone 210 canbe a closed pipe, a draft-tube reactor, a stirred tank reactor, or otherreactor. As an option, the reaction can occur down a length of spiralingpipe (as the reaction zone 210) to a vessel 211. The reaction zone canbe designed to provide turbulence to increase mixing of the reducingmetal and metal halide during the reaction, such as by using spiraledpiping or a stirred reactor, or other designs. This vessel 210 cancollect the product by utilizing the high density of reaction productmetal and allowing it to settle to the bottom. The excess sodium and/orpotassium or the excess aluminum or magnesium or titanium 215 can flowout of the vessel 211 through an outlet, such as pour spout or decanteror siphon, and then through a filter 212 and a cooler 213 before makingit back to the storage tank 201 for reuse.

After the metal production, the settling tank 211 can be used as a bakeout vessel. The vessel 211 can be heated to high temperatures until itis void of all excess sodium and/or potassium, or the excess aluminum(or magnesium or titanium), leaving behind a metal/salt mixture. Thismixture can be used for post processing.

In the metal halide powder feed system, the feeding of the metal halidepowder preferably should occur in an inert atmosphere due to itsreactivity in air. As such, the powder transfer to the feed system andall working parts of the feeder itself preferably are maintained in aninert atmosphere, such as an argon atmosphere. If an inert atmosphere isnot kept, there can be a risk of heavy chloride corrosion as well ascontamination of the product. As an option, a glove box set up aroundthe feeding system can be used. Once the metal halide powder is fed, itpreferably is incorporated into the sodium and/or potassium or into thealuminum and/or magnesium and/or titanium in a manner that promotescomplete reaction to metal. It has been observed in experiments thatmetal halide powders, such as HfCl₄ powder, is not wetted by liquidsodium, and does not easily disperse, and can form a crust of metal thatsurrounds and shields unreacted powder from the sodium and/or potassium.The funnel/eductor design is used to disperse the powder into coldsodium and/or potassium or into cold aluminum (or cold magnesium or coldtitanium) before sucking it down into the hot sodium and/or potassium,or the hot aluminum (or hot magnesium or hot titanium) and initiatingthe reaction. This method can provide enough agitation to get the metalhalide, such as HfCl₄, mixed and promote reaction with sodium and/orpotassium, or the aluminum (or magnesium or titanium) once mixed intothe hot sodium and/or potassium or the hot aluminum (or hot magnesium orhot titanium). Eductors work based on set flows and pressures on theinlets and the outlet. If the suction is too great for the slurry feed,argon gas can be sucked into the system and can cause problems. As such,a control system can be used to control each flow rate as well as thelevel in the funnel above the eductor. Further, heat tracing preferablyis used throughout the system where reducing metal is stored and passesto monitor the temperatures and for control thereof. If a cold spot inthe system should develop, it may cause the sodium or other reducingmetal used to freeze and possibly plug up the system.

The settling/bake-out vessel can be a dual purpose piece of equipmentthat can collect and purify the product. If not transferred or recycledto tank 201 during the reaction and process as indicated, in postproduction, the vessel can be full of excess molten reducing metal thatneeds to be removed. This excess molten reducing metal can be removed byraising the temperature to extremely high levels and evaporating themolten reducing metal out. This high temperature may limit theapplicable materials of construction and designs. Following this moltenreducing metal removal, the vessel itself can be removed from the systemfor product recovery.

In FIG. 3, a method of making a masterbatch of the present invention,indicated as 300, is shown. In this method, a solid metal halide 307 isused and a tank 301 of aluminum (or magnesium or titanium) is used as asource of reducing metal. Features and steps 302, 314, 303, 304, 305,306, 307, 308, 309, and 310 can be similar to or the same as featuresand steps 202, 214, 203, 204, 205, 206, 207, 208, 209, and 210,respectively, as described with respect to method 200 in FIG. 2, andreference is made thereto. The reducing metal is introduced instoichiometric excess with respect to the metal halide in this method,such as in a range described herein. The method 300 of FIG. 3 differsfrom the method 200 shown in FIG. 2 with regards to the materials thatare removed and retained in the collection tank that receives materialsfrom the reaction zone. In the method 300 of FIG. 3, thevolatization/masterbatch tank 311 is used to collect reaction productmetal and a salt produced in the reaction zone 310, and also excessaluminum reducing metal (or excess magnesium metal or excess titaniummetal). The salt, and not the excess aluminum (or magnesium or titanium)reducing metal, is separated out to obtain a metal masterbatchcomprising at least a portion of the aluminum (or magnesium or titanium)reducing metal and reaction product metal. The aluminum (or magnesium ortitanium) and reaction product metal can be intermixed as a uniform orsubstantially uniform physical mixture thereof, which forms or can beformed into a unitary solid mass of material.

In FIG. 4, a method of making a metal powder of the present invention,indicated as 400, is shown. In this method, a liquid metal halide 405 isused instead of a solid metal halide as used in the methods of FIGS. 2and 3. A tank 401 of sodium and/or potassium, or a tank 401 of aluminum(or magnesium or titanium) is used as a source of reducing metal. Thereducing metal is introduced in stoichiometric excess with respect tothe metal halide in this method, such as in a range described herein.Features and steps 402, 414, 403, 404, 406, 407, 408, 409, and 415 canbe similar to or the same as features and steps 202, 214, 203, 208, 210,211, 212, 213, and 215, respectively, as described with respect tomethod 200 in FIG. 2, and reference is made thereto. The liquid metalhalide 405 can be introduced into the heated molten reducing metal usingan injection or pumping device, such as using pressurized inert gas toforce metal flow.

In FIG. 5, a method of making a masterbatch of the present invention,indicated as 500, is shown. In this method, a liquid metal halide 505 isused instead of a solid metal halide as used in the methods of FIGS. 2and 3, and a masterbatch is formed in a volatization/masterbatch tank507 used similarly to the tank 311 as used in the method 300 shown inFIG. 3. In method 500, tank 501 of aluminum (or magnesium or titanium)is used as a source of reducing metal. Features and steps 502, 514, 503,504, 506, 507, and 508 can be similar to or the same as features andsteps 302, 314, 303, 308, 310, 311, and 312, respectively, as describedwith respect to method 300 in FIG. 3, and reference is made thereto. Theliquid metal halide 505 can be introduced into the heated moltenaluminum (or magnesium or titanium) reducing metal using an injection orpumping device similar to or the same as that described for use in themethod 400 of FIG. 4. As in the examples of the methods shown in FIGS.2-4, the reducing metal is introduced in stoichiometric excess withrespect to the metal halide in this method as well, such as in a rangedescribed herein.

Additional information on the metal halide reaction and productprocessing which are related to methods described herein are provided inthe following sections.

Metal Halide Reduction

In the metal halide reduction step, when using the indicated liquid orsolid forms thereof, the metal halide is reduced to a metal and a metalsalt (e.g., from the reducing metal reacting with the halide from themetal halide) is produced as a byproduct.

As indicated, the metal halides can be reacted with a stoichiometricexcess of the reducing metal in methods of the present invention. Metalhalides that can be reacted include, for example, one or more halides oftantalum, nickel, aluminum, zirconium, vanadium, tin, titanium, silicon,niobium, or hafnium, or any combination thereof. Other examples arementioned earlier. The metal halide can be a metal chloride. The metalhalide can be a metal bromide or metal iodide. The reducing metal isdifferent from the metal of the metal halide, when one metal halide isused. The reducing metal (in molten state) can be or include a Group Imetal(s) or aluminum. Examples of reductions include: TaCl₅ reduced bysodium; TaCl₅ reduced by a mixture of sodium and potassium; HfCl₄reduced by sodium, HfCl₄ reduced by a mixture of sodium and potassium;HfCl₄ reduced by aluminum; a mixture of TaCl₅ and NiCl₂ reduced by amixture of sodium and potassium; AlCl₃ reduced by sodium; ZrCl₄ reducedby sodium; ZrCl₄ reduced by aluminum; VCl₄ reduced by sodium; SnCl₄reduced by sodium; TiCl₄ reduced by sodium; and SiCl₄ reduced by sodium.Subhalides (e.g., halides of lower oxidation states of the metalelements that contain less halide (e.g., TiCl₂ or TiCl₃) than its commonhalide (e.g., TiCl₄)), including subchlorides, can also be reduced inthe same manner, for example, titanium, zirconium, or tin subchlorides.Examples of reduction reactions can proceed according to Equations (2A),(2B), (2C), (2D), (2E), (2F), or (2G):

TaCl₅(s or l)+5Na(l)-->Ta(s)+5NaCl(s)  (2A),

HfCl₄(s or l)+4Na(l)-->Hf(s)+4NaCl(s)  (2B),

3TiCl₄(l)+13Al(l)-->3TiAl₃(s)+4AlCl₃(g)  (2C),

SiCl₄(l)+CCl₄(l)+8Al(l)-->SiC(s)+8AlCl₃(g)  (2D),

SiCl₄(l)+CCl₄(l)+4Mg(l)-->SiC(s)+4MgCl₂(l)  (2E)

ZrCl₄(s or l)+CCl₄(l)+2Ti(l)-->ZrC(s)+2TiCl₄(g)  (2F)

NaAlCl₄(l)+TiCl₄(l)+7Na(l)→TiAl(s)+8NaCl(s)  (2G)

In order to generate flowable reducing metal for use in the reaction,the reducing metal is heated to a temperature above its melting pointand below its boiling point before it is combined with metal halide andpassed into a sealed reaction vessel that is substantially free ofoxygen and water. Higher temperatures can lead to the generation ofreducing metal vapors that must be controlled. Sodium, for instance, hasa melting point temperature of about 98° C. and a boiling pointtemperature of about 883° C. (at about 1 atmosphere pressure). Aluminumhas a melting point temperature of about 660° C. and a boiling pointtemperature of about 2470° C. (at about 1 atmosphere pressure). It canbe advantageous to stay at least 50° C., or at least 100° C., or atleast 200° C., or at least 300° C. above the melting point. The heatedreducing metal can be initially heated sufficiently to provide apumpable molten material, and the mixture resulting from its combinationwith metal halide can have a temperature sufficient to support the metalhalide reduction reaction by the initial heating, additional heatingbefore combination with metal halide, or additional heating aftercombination with metal halide, or any combination thereof. Beforecombining with the metal halide, the molten reducing metal, depending onthe metal, can be heated and maintained at a temperature of from about150° C. to about 850° C., or from about 150° C. to about 350° C., orfrom about 200° C. to about 250° C. For example, when the reducing metalis sodium, more typical reaction temperatures are from 150° C. to 350°C., though temperatures up to about 850° C. or other temperatures arepossible. In some instances, where the molten reducing metal is sodium,the sodium is heated and maintained at a temperature of from about 600°C. to about 700° C. until combined with the metal halide.

As indicated, the reaction zone can be a closed pipe (e.g., a spiraledpipe), a draft-tube reactor, a stirred tank reactor, or other reactor.The reaction zone preferably creates turbulence which encourages mixingof the reducing agent and metal halide in the reaction zone. As anoption, a stirred reactor that can be used, such as described in U.S.patent application Ser. No. 15/051,267, which is incorporated in itsentirety by reference herein.

The reaction zone can be a sealed, reaction chamber, which can be anairtight glovebox. An airtight glovebox can be constructed largely ofglass plates attached to a metal frame. A glovebox permits an operatorto manipulate objects within the glovebox while maintaining an inertreaction environment. The reaction chamber can be a bench-top glovebox,or it can be a larger glovebox suitable for pilot scale operations, inwhich case it may have work stations where several operators can accessthe interior of the glovebox. The reaction chamber can also be largeenough to house industrial- or commercial-scale reaction vessels. Forcommercial scale production, an airtight vessel having automated loadingand unloading can be used.

For any of the methods of the present invention, including those shownin FIGS. 1-6, optionally, other reactants can also be included duringthe metal halide reaction which do not interfere with that reaction. Forinstance, a carbide forming, or nitride forming, or boride formingcomponent (i.e., ceramic forming components) can be added to the metalhalide or to the molten reducing metal or both, wherein at least oneother metal compound that comprises a metal carbide, a metal nitride, ora metal boride or any combination thereof can be formed. The carbideforming component can comprise carbon containing gas, carbontetrachloride, or solid carbon. The boride forming component cancomprise boron trichloride or one or more boron hydrides. The nitrideforming component can be titanium nitride (TiN). The amount of metalcarbide, metal nitride, and/or metal boride, or any combination thereof,in the reaction products in lieu of the metal formed, can be from about10 wt % to about 100 wt % of the total weight reaction product (e.g,from about 40 wt % to 100 wt %, or from 60 wt % from 100 wt % or from 90wt % to 100 wt %, or from 98 wt % to 100 wt %). From 40 wt % to 100 wt%, or from 60 wt % from 100 wt % or from 90 wt % to 100 wt %, or from 98wt % to 100 wt % of the metal formed can be converted to the metalcarbide, metal nitride, or metal boride in the reaction. The otherreactants, such as the carbide or boride or nitride forming componentcan be added at any stage of the process, such as at or before thereaction zone, or can be present with the reducing metal or with themetal halide introduction point, or be separately introduced using anadditional inlet to the flow of the reducing metal or metal halide, orboth.

Recycling of Excess Reducing Metal

In another step of the methods such as shown in FIGS. 2 and 4, theexcess unreacted molten reducing metal can be separated so that it canpreferably be reused in another reduction reaction. The excess reducingmetal can be as much as 50% by weight, or more in some cases, of thestarting amount of molten reducing metal. As illustrated in FIG. 6, theexcess molten sodium and/or potassium, or the excess molten aluminum (ormagnesium or titanium) reducing metal 660, along with the metal powderand the sodium salt and/or potassium salt, or the aluminum salt (ormagnesium salt or titanium salt) formed during the metal halidereduction reaction step, can be decanted into a bake out vessel 610. Thebake out vessel 610 can have a lip 615 that can facilitate the placementof a lid 620 on top of the bake out vessel 610. The bake out vessel 610can have one or more ports 630 that can be used to remove excessreducing metal material from the bake out vessel 610. The port 630 canbe adjustable so that they can extend to differing depths within thebake out vessel 610. The port 630 can be formed of a non-conductingceramic in order to reduce long-range electron mediated reduction.

To recover the molten reducing metal, the bake out vessel can be heatedto just above the melting point of the metal salt formed as a reactionbyproduct. For example, when the metal halide is hafnium chloride andthe reducing metal is sodium, the salt produced is sodium chloride,which has a melting point of approximately 801° C. In this example, thebake out vessel 610 can be heated to just above 801° C., which is justabove the melting point of sodium chloride. At this temperature, thesodium chloride salt begins to melt and separate from the excess(unreacted) sodium reducing metal, thereby creating a salt bath 640 anda molten reducing metal phase 660. A small amount of the sodiumdissolves in the molten sodium chloride salt (approximately 2 molar % at801° C.). The salt bath phase 640 includes sodium salt 641 and the metalpowder 645 created by reducing the metal halide. A first outlet or port630 can use used to pour off (decant) or siphon out the bulk of theexcess sodium molten reducing metal 660 by gravity (drain) or byapplying a negative relative pressure (siphon) in a capture tank. Thismolten sodium reducing metal 660 that has been poured off or siphonedoff can be captured in a capture tank and reused, such as shown in FIGS.2 and 4.

The bake out temperature can be adjusted by adding other salts andcreating an eutectic system. For example, a 52:48 (by wt) mix of calciumchloride and sodium chloride melts at approximately 500° C. Thus, thebake out can occur in a lower temperature range (e.g., where stainlesssteel can be used instead of more expensive metals). By operating at alower temperature, the surface area of the resulting metal powder canalso be increased since a higher temperature leads to increasedsintering.

Care should be exercised to determine the boundary between the moltenreducing metal and the salt so that only the molten reducing metal isremoved. It may not be possible to drain or siphon off all of the excessmolten reducing metal 660. For example, there may be a layer of reducingmetal 660 that is a few millimeters thick that remains after draining orsiphoning. As an option, the amount of excess reducing metal (e.g., 1)Na and/or K, or 2) Al and/or Mg and/or Ti) after draining or siphoningcan be 5,000 ppm or less in the metal and salt products, such as lessthan 3,000 ppm, or less than 2,000 ppm, or less than 1,000 ppm, or lessthan 500 ppm, or less than 250 ppm, or from 0 ppm to 5,000 ppm, or from10 ppm to 2,000 ppm, or from 100 ppm to 1,500 ppm.

Alternatively, or in addition, residual reducing metal can be reactedwith an alcohol, such as methanol.

Once the reducing metal layer has been removed or substantially removedto the ppm levels indicated above, as an option, the remaining reducingmetal can be reacted with an anhydrous chloride, such as anhydroushydrogen chloride (HCl) or chlorine gas (Cl₂). However, the hydrochloricacid can attack the metal particles that have been formed. In order toprotect the metal particles, a salt can be added to the bake out vessel610 either prior to or after pouring the molten reducing metal, salt,and metal powder into the bake out vessel 610. Typically, the salt addedis the same salt formed during the reduction of the metal halide by thereducing metal. The salt produced in the neutralization reactiontypically fills the voids in the metal, and chlorides can thereforeattack the metal. By providing a layer of molten salt, direct contactbetween the halides and the metal can be reduced. Thus, the chloridetends to neutralize the free sodium, which has valence electrons havinga long mean free path in the molten salt.

The resulting product can be a metal powder at least partially or fullyencapsulated in salt. The salt can have a glass-like appearance becauseit was melted and cooled.

Salt Removal

In a further step, the salt can be removed. Metal powder having a highersurface area is generally less dense and contains more salt in narrowervoids.

In a first method of removing the excess salt from the metal particles,the metal particles encapsulated in salt are washed with water.Preferably, the metal particles encapsulated in salt are transferred toa new vessel prior to the water wash in order to prevent oxidation ofthe bake out vessel. Frequently, the metal particles are washed inserial batches in a metal beaker or other metal container so that theconcentration of salt is less than 1 ppm. An example reaction forremoving excess salt is Equation (3), after which the liquids anddissolved solids are removed:

Ta(s)+5NaCl(s)+2H₂O(l)->Ta(s)+5NaCl(aq)+2H₂O(l)  (3)

In a second method of removing the excess salt from the metal particles,the salt can be evaporated. One method of evaporating the salt is bysweeping an inert gas, such as argon, through the chamber at atemperature close to or above the melting point of the salt, such thatthe salt has an adequate vapor pressure to permit it to be removed in areasonable time. The salt vaporizes, leaving behind the metal particles.The procedure can be conducted within a rotary furnace, which can limitthe formation of a sponge from the metal particles. The inert gas can berecycled.

In a third method of removing the excess salt from the metal particles,ultrafiltration can be used to remove excess salts. One such system isprovided by Koch Membranes.

Metal Powder Recovery

In another further step, the metal particles are recovered and can besubsequently dried if desired. The particles can be dried in a vacuumoven. After drying the metal particles can be collected and recovered asa free flowing powder.

When the metal powder is exposed to air, it can be highly flammable, andits dust can be explosive. Thus, it must be handled with care, andpreferably in an inert atmosphere, until the powder has beenconsolidated into a desired final form or else until the powder surfacehas been passivated by controlled exposure to oxygen.

Masterbatch Recovery

In masterbatch production, where aluminum is used as the reducing metaland aluminum trichloride (AlCl₃), also referred to as aluminum chloride,is the salt formed in the reaction with metal halide, the aluminumtrichloride can be selectively separated and removed to leave thereaction product metal and excess aluminum as a masterbatch. Thesublimation pressure of the aluminum trichloride reaches one atmosphereat about 179° C. to 183° C. at approximately 1 atmosphere pressure, andthe melting-point of aluminum trichloride at 2.5 atmospheres pressure isabout 190° C. to 194° C. In view of these properties of aluminumtrichloride, the contents of the holding tank can be heated underapproximately one atmosphere pressure to at least about 179° C. to 183°C. and below the boiling temperature of aluminum (about 2470° C.) andthe reaction product metal (e.g., Hf melt. pt.=about 2233° C., boil.pt.=about 4600° C.) to selectively volatize the aluminum trichloride andseparate it from the other contents in the holding tank. Similarprocesses and reactions can be used when the reducing metal is magnesiumor titanium and the a magnesium chloride or titanium chloride, forinstance is the salt formed.

The present invention will be further clarified by the followingexamples, which are intended to be exemplary of the present invention.

EXAMPLES Example 1 (Theoretical Example)

Using a process flow as illustrated in FIG. 2, a storage tank containing200 gallons of molten sodium is pumped through a continuous loop usingan electromagnetic pump. There is a cold trap installed on the loop thatis used to remove contaminants prior to starting up production. Once thecontaminants are removed the cold trap is valved off until needed again.The electromagnetic pump pumps the molten sodium to a flow split. Theflow to the cooler can be roughly 3 GPM and the flow to the heater canbe roughly 17 GPM. The flows can be controlled using valves and Coriolisflow meters.

The cold sodium stream flows around a funnel. The HfCl₄ powder is addedto this funnel. The sodium flows around the funnel and collects thepowder and it is drawn through an eductor. The eductor uses the hotsodium flow as the motive fluid sucking the HfCl₄ slurry into it. Theadditional heat provided by the hot sodium stream initiates thereduction reaction. Feeding of the HfCl₄ powder occurs in an inertatmosphere due to its reactivity in air. As such the powder transfer tothe feed system and all working parts of the feeder itself is maintainedin an inert atmosphere. A small glove box is set up around the feedingsystem. The reaction occurs down a length of spiraling pipe (reactionzone) to a vessel. This vessel collects the product by utilizing thehigh density of Hf metal and allowing it to settle to the bottom. Theexcess sodium flows out of the top of the vessel through a filter and acooler before making it back to the storage tank.

After the metal production, the settling tank is used as a bake outvessel. The vessel is heated to high temperatures until it is void ofall excess sodium, leaving behind a metal/salt mixture. This mixture istaken for post processing by NSP.

Additional examples are provided in the following section.

Example 2: Halide Powder Feed Test Instrumentation Setup

A powder trickier was used for all halide powder trials to feed thereactant powders to a beaker containing alkali metal(s). This powderfeeder consists of an adjustable hopper, discharge tube, stand, and2-speed control pad. All reactant powders flowed readily through thetube given the vibration frequency at hand, except the TaCl₅ and NiCl₂50/50 powder blend. This powder blend packed tightly inside both thetube and the hopper base. As a result, remaining powder was fed to thereaction beaker using a “hand-add” approach with a spatula for the TaCl₅and NiCl₂ 50/50 blend.

All tests utilized an IKA 70 Watt mixer with the capability of producingspeeds from 60 to 2000 rpm. A stainless steel, 1.20 inch diameter,turbine impeller blade was utilized for the first two tests performed,TaCl₅ in excess sodium. All subsequent tests were performed using astainless steel, 1.65 inch diameter, Cowles blade impeller to improvethe incorporation of the reactant powder in the alkali metal. Eventhough the mixer maximum capacity was specified as 2000 rpm maximum, themixer was utilized at speeds as high as 2135 rpm in the powder feedtests.

A stainless steel 2000 mL beaker was implemented as the reaction vesselfor all tests. A lid was constructed for trial 3 with 3 ports for themixer impeller, powder feed tube, and alkali metal temperaturethermocouple (TE-0111A). The lid eliminated a large amount of dustingwithin the glovebox while allowing for the reactant powder to be feddown into the alkali metal via a vertical feed tube. The 4th and 5thtrials used a similar lid with a reduced diameter port to furtherminimize dusting to the glovebox.

A test setup used for this example is shown and described with referenceto FIG. 3 as described in U.S. patent application Ser. No. 15/051,267,which is incorporated in its entirety by reference herein. The stainlesssteel beaker, V-0100, contained the alkali reducing metal. The reactionbeaker was maintained at 200-250° C. using a heater band (controlled viaTC-0111) and a hot plate (controlled via TC-0110). The variation inalkali metal temperature was based upon the reactivity of the halidepowder during each trial via physical observation. Halide powders werepre-weighed using scale WI-0120 and fed from the powder feeder, F-0125,to V-0100 in 5-10 gram increments.

Argon was fed from an argon supply Dewar to the glovebox at a flow rateof 110 standard cubic feet per hour (scfh). Argon pressure was regulateddown to 20-30 psig. The glovebox oxygen and moisture content wasrecorded prior to the start of each trial. Before any halide powderswere exposed to the glovebox internals, the blower was de-energized andthe purifier was isolated in an effort to preserve the integrity of thepurifier. With the purifier isolated from the system, oxygen content wasnot accurately displayed on the glovebox control panel because theoxygen sensor was also sensitive to chlorides, and therefore provided aninaccurate reading due to the presence of chloride vapors in theglovebox.

A vacuum filtration system was incorporated for the trials using NaK.This system consists of a filtration separation vessel, V-0134, thatcontains a 10 micron screen inserted within a stainless steel cup toretain the solids. A catch vessel (flask), V-0135, was used to preventany filtered NaK carry-over and to protect the vacuum pump, PU-0130.This vacuum filtration set-up was also used to perform the methanol washsteps within product recovery when NaK was utilized.

Test Procedure and Results

A first experiment was conducted to assess the minimum reactiontemperature and mixing parameters. In this first experiment, an inertatmosphere having as little oxygen and moisture as possible wasestablished in the glovebox. The hot plate and heater bands wereenergized and set to 200° C. Once the alkali metal was up totemperature, a pinch test was performed by adding a small amount ofreactant powder to the alkali metal. The pinch test must be performedwith the lid removed from the vessel to observe for signs of reaction(such as a change in color or the generation of smoke). If no sign ofreaction was observed at 200° C., then the temperature was increased inincrements of 50° C. and the pinch test was repeated until a reactionwas observed. All reactions were performed at 250° C. or less.

The halide powders were manually weighed in 5-10 gram increments beforebeing added to the hopper. Powder was fed from the hopper to the vessel,with pauses in feeding when smoking was observed. When the reaction stepwas completed, the mixer, heater band, and hot plate were de-energizedto allow for the system to cool before the start of product recovery.

A total of five experiments was performed; two utilized TaCl₅ and moltensodium, whereas the remaining three reacted TaCl₅, HfCl₄, and a 50/50(wt %) mix of TaCl₅ and NiCl₂, each with NaK alloy. A consolidation ofthe test results displaying the amount of fed halide powder, the amountof alkali metal used, and the final amount of collected product aftervacuum drying can be viewed for each test in Table 1 below.

TABLE 1 Reactant Charges and Fractional Yield Summary Charged RecoveredFractional Yield Fed Halide Alkali Product (actual/theoretical TestPowder (g) Metal (g) (g) product) 1. TaCl₅ in 0.50 90.00 0.05 19.8%Excess Na 2. TaCl₅ in 19.15 957.00 0.50 5.2% Excess Na 3. TaCl₅ in 41.16748.00 13.60 65.4% Excess NaK 4. HfCl₄ in 23.78 718.70 9.80 74.0% ExcessNaK 5. TaCl₅/NiCl₂ 19.26 728.40 5.20 56.4% in Excess NaK

At the start of Test 5, NiCl₂ showed no sign of reaction at 200° C. whenperforming a pinch test; however, a reaction was visible at 250° C.Therefore, Test 5 was performed at 250° C.

The 50/50 wt % NiCl₂/TaCl₅ (Test 5) powder mix tightly packed within thehopper feed tube, as well as the base of the hopper, multiple times. Asa result, approximately half of the feed was added to the NaK-containingvessel manually using a spatula.

For the first two trials utilizing sodium, filtration took place in thereaction beaker, with the second test using a removable screen (<500mesh) placed within the vessel. Material was scraped from the reactionvessel (and screen for the second test) before adding methanol to reactresidual sodium held up within the product. The reaction products werecentrifuged for 0.5-2.0 hours at 3000 rpm and decanted, and a secondmethanol wash was repeated, followed by a de-ionized water wash topassivate the tantalum product. A second de-ionized water wash wasperformed using nitric acid to achieve a solution with a pH of 2. Afterdecanting, the sample was then vacuum dried overnight at 95° C.

For the trials performed with NaK, the vacuum filtration system in theglovebox was utilized to remove the excess NaK from the reacted product.Two methanol washes were performed to react any NaK held up with theproduct, and vacuum filtration was used to remove excess solvent withinthe product cake. As with the first two tests, methanol washing wasfollowed by a de-ionized water wash in the glovebox to passivate theproduct followed by centrifugation at 3000 rpm for 30 minutes anddecanting. A total of five or six water washes were performed before theproduct was vacuum dried overnight at 85-95° C. Each test performed withNaK utilized varying deionized (DI) water solutions based on the productisoelectric points. Table 2 describes the pH of the solutions used forwater washing as well as the number of washes performed. Solution pH wasadjusted using nitric acid or sodium hydroxide.

TABLE 2 Water Wash Criteria for Products Generated Using NaK DI WaterWash No. of Performed Test Solution pH Washes 3. TaCl₅ in Excess 2-3 6NaK 4. HfCl₄ in Excess 7 6 NaK 5. TaCl₅/NiCl₂ in Half at 2.50-3.0; Halfat 10-11 5 Excess NaK

Other observations include the following:

Significant dusting was observed in the glovebox for Tests 1 and 2,which were performed with an open lid. The rotation of the mixer shaftcan create argon currents that disperse some of the powder feed. Dustingwas observed again for Test 3, but dusting significantly decreased sothat very little was observed for Tests 4 and 5, which utilized a lid.

When draining excess sodium from the product in Test 2, it was difficultto determine if the sodium drained through the inner mesh strainerassembly or if a hole was present in the mesh. Furthermore, some darkmaterial (most likely tantalum) was removed with the excess sodium, andcaught in the <500 mesh strainer.

Sufficient mixing was established with the mixer running at 1625-1675rpms in Test 3; however, once powder addition began, the mixing speedwas increased to 1750 rpms to maintain a good vortex and surfacemovement.

The hafnium tetrachloride powder used in Test 4 was denser and chunkierthan the tantalum pentachloride previously used. Larger HfCl₄ chunksappeared to sink in the NaK with no visible signs of reaction, whereasthe loose, fine powder generated smoke and changed in color from whiteto black upon contact with NaK. The HfCl₄ powder was filtered to removethese larger chunks prior to feeding the hopper and starting thereaction.

At the start of Test 5, NiCl₂ showed no sign of reaction at 200° C. whenperforming a pinch test; however, a reaction was visible at 250° C.Therefore, Test 5 was performed at 250° C.

The 50/50 wt % NiCl₂/TaCl₅ powder mix tightly packed within the hopperfeed tube, as well as the base of the hopper, multiple times. As aresult, approximately half of the feed was added to the NaK-containingvessel manually using a spatula.

The amount of fed halide powder used in the last, fifth trial is a bestestimate due to losing approximately 0.86 g when the feed tube on thelid assembly plugged during the feeding process.

Salt Concentration Test

A salt concentration test was performed to assess the quantity of metalhalides that can be added while maintaining a vortex. A total of 797.17grams of sodium were used, and a total of 477.69 g NaCl were added overthe course of the trial. The first five salt charges were added inincrements of 10 g, and all subsequent charges were fed in 25 gincrements.

After feeding 154.88 g of NaCl, a white-grey film skimmed over thesurface of the sodium and surface motion was halted. When increasing themixer speed from 1611 to 1750 RPMs, surface motion resumed in pockets.At a mixing speed of 1950 rpms, swirling became visible, but a vortexwas still not observed. At 2008 rpms, an off-centered vortex developedto the left of the mixer shaft.

Once NaCl addition reached 399.74 g, surface movement again ceased, butregenerated after four minutes of no movement. After adding 424.74 g ofNaCl, movement again ceased, but was re-initiated by probing the surfacewith a flat blade. The salt feed was stopped at 477.69 g, afterchangesin fluid density and viscosity were observed and surface mixing nolonger occurred.

All tests demonstrated that the halide powder-alkali metal reactions canbe performed at 200° C. except for NiCl₂, which should be reacted withalkali metals at 250° C.

A dispersion of sodium and sodium chloride can have approximately 33 to37 wt % salt before changes in fluid density and viscosity were observedand surface mixing no longer occurred.

Example 3: Halide Powder and Liquid Initiation Test InstrumentationSetup

A second set of experiments was conducted to verify the reactivity ofvarious powder and liquid halides with sodium metal. All tests wereperformed in a glovebox, inerted with argon to eliminate oxygen andmoisture from the atmosphere.

Powder halide transfer: Aluminum Trichloride and Zirconium (IV) Chloridepowders were transferred into weighing dishes using a microspatula. Thepowders were then poured into the reaction cups from the weighingdishes.

Liquid halide transfer: Vanadium (IV) Chloride, Tin (IV) Chloride,Titanium (IV) Chloride, and Silicon Tetrachloride were transferred intothe reaction cups using 1 mL syringes. For each liquid halide, a volumeof 0.1 mL was transferred into a syringe. The syringes were then placedin the glovebox. The syringes were then used to inject drops of eachliquid halide into a reaction cup containing molten sodium metal.

Reaction vessel: Stainless steel 2.5 oz. cups were implemented as thereaction vessels for all tests. When not in use, stainless steel foilwas placed on top of each reaction cup.

A test setup used for this example is shown and described with referenceto FIG. 4 as described in U.S. patent application Ser. No. 15/051,267,which is incorporated in its entirety by reference herein. Eachstainless steel cup, V-0100 through V-0600 contained sodium metal. Thereaction cups were maintained at 240−260° C. using a hot plate (manuallycontrolled via TC-0110). Halide powders were pre-weighed using scaleWI-0120 and poured into V-0100 and V-0200. The scale used to weigh thepowder halides only displays increments of 0.1 grams; therefore, theamount of halide powders added to each reaction cup was known to be lessthan 0.1 grams. Halide liquids were injected into the reactions cupsusing 1 mL syringes. Because of the limited dexterity in the gloveboxand hazards associated with handling syringe needles, the liquid halideswere transferred from storage bottles into syringes under the fume hood.The syringes were then placed in the glovebox. For each halide liquid,0.1 mL or less was injected into the reaction cups V-0300 throughV-0600. The setup for the liquid halides was the same with the exceptionthat four reaction cups were used instead of two.

Argon was fed from an argon supply Dewar to the glovebox at a flow rateof 65-70 scfh. Argon pressure was regulated down to 20-30 psig.

The glovebox oxygen and moisture content was recorded prior to the startof each trial. Before any halide powders were exposed to the gloveboxinternals, the blower was de-energized and the purifier was isolated inan effort to preserve the integrity of the purifier. With the purifierisolated from the system, oxygen content was not accurately displayed onthe glovebox control panel.

Test Procedure and Results

Each test began with equipment set-up in the glovebox, and establishingan inert atmosphere. The hot plate was energized and set to 250° C. Inorder to reach and maintain a sodium temperature of 250° C., the hotplate was set between 350° C. and 400° C. Once the sodium metal was upto temperature, the halides were added to the reactions cups one at atime. The tests were performed with the lid (foil) removed from the cupto observe signs of reaction (such as a change in color or thegeneration of smoke). If no sign of reaction was observed at 250° C.,then the temperature was increased in increments of 50° C. and the testwas repeated until a reaction was observed. All reactions were performedat 250° C. in order to establish a safe minimum temperature.

Two experiments with halide powders were performed utilizing powderedAlCl₃ and ZrCl₄ reacted with molten sodium. Table 3 lists theconsolidated test results displaying the amount of halide powder added,the amount of sodium metal used, the reaction temperature, and anyobservations during the reaction.

TABLE 3 Halide Powder Reaction Results Charged Halide Sodium PowderMetal Reaction Test Added (g) (g) Temp (C.) Observations 6. AlCl₃ in<0.1 9.7 245 Color change to dark gray Excess Na 7. ZrCl₄ in <0.1 9.9250 Color change to dark gray Excess Na

Other observations from the test include the following: ZrCl₄ did notreact as immediately as AlCl₃.

Four experiments were performed utilizing liquid VCl₄, SnCl₄, TiCl₄, andSiCl₄ reacted with molten sodium. Table 4 lists the consolidated testresults displaying the amount of halide liquid added, the amount ofsodium metal used, the reaction temperature, and any observations duringthe reaction.

TABLE 4 Halide Reaction Results Halide Charged Liquid Sodium Added MetalReaction Test (mL) (g) Temp (C.) Observations 8. VCl₄ in 0.1 10.0 245Color change to black Excess Na Temperature increase of 3° C. 9. SnCl₄in 0.03 9.9 256 Color change to dark gray Excess Na Blue flame SomeSnCl₄ evaporation 10. TiCl₄ in 0.02 10.0 251 Color change to blackExcess Na Some TiCl₄ evaporation 11. SiCl₄ in 0.08 10.1 251 SiCl₄ mostlyevaporated on Excess Na sodium surface Color change to dark gray

Other observations from the tests include the following:

After transfer into the syringes, fuming out of the end of the needlewas noticed with VCl₄, SnCl₄, and TiCl₄. In the case of SnCl₄ and TiCl₄,fuming stopped once the needles were inserted into rubber stoppers. Inthe case of VCl₄, fuming continued for 2 minutes after the needle wasinserted into the rubber stopper.

There was some pressure build up with the VCl₄ syringe. Some VCl₄ wasreleased from the syringe when the stopper was removed from the end ofthe needle while in the glovebox.

TiCl₄ changed from clear to yellow while in the syringe.

There appeared to be more oxide on the sodium surface for the SiCl₄reaction which could have resulted in the majority of the SiCl₄ layingon the surface and slowly evaporating instead of reacting. SiCl₄ is alsomore volatile than the other liquid halides tested.

AlCl₃, ZrCl₄, VCl₄, SnCl₄, TiCl₄, and SiCl₄ all react with sodium atapproximately 250° C. There is potentially some evaporation when theliquid halides are introduced to sodium at 250° C.

Example 4: Metal Powder Characterization

Particle flow can be measured according to a standardized protocol, suchas by using a Hall flow meter according ASTM International StandardB213.

Molecular content of the metal powders produced by the methods describedherein can be determined using LECO testers. For example, nitrogen andoxygen content can be tested with LECO Model TC436DR. Carbon and sulfurcontent can be tested with LECO Model CS444LS. Nitrogen, oxygen, andhydrogen content can be tested with LECO Model TCH600.

Purity can be assess by glow discharge mass spectrometry or inductivelycoupled plasma mass spectrometry.

Example 5: Titanium Powder

140 g of sodium metal was melted and brought to 250° C. in an Inconelreactor vessel. The sodium was then stirred using a Cowles blade mixerrotating at 2200-2300 rpm. Liquid titanium chloride (from Sigma Aldrich)was fed over approximately 1 hour into the stirred sodium, until 60 g oftitanium chloride had been added, at which point the reaction was haltedby releasing the gas pressure on the halide feed. At the end of thereaction, the vortex in the sodium had substantially disappeared.

Once the reaction was completed, the reactor vessel was sealed,transferred to a furnace, and heated to 825° C. for four hours to reducethe surface area of the titanium metal produced in the reaction.

After the high temperature treatment, the unreacted sodium was removedfrom the reaction products and the titanium powder, coated in salt, waswashed in water to remove the coating of sodium chloride encapsulatingthe metal. Washing continued until washwater conductivity fell below 2microsiemens.

The recovered titanium powder was dried overnight in a vacuum oven at100° C. The titanium powder thus produced was analysed by inductivelycoupled plasma mass spectrometry (ICP-MS) and LECO instruments, and wasfound to contain below 150 ppm iron, below 300 ppm total transitionmetals, and below 3000 ppm oxygen. The results demonstrate that thetitanium powder falls within the purity limits as described in UNS No.R50550.

Visual assessment of SEM images showed particle agglomeratespredominantly in the 50 micron range, with primary structure mainly at3-5 microns.

Example 6: Hafnium Metal

113 g of sodium metal was melted and brought to 250° C. in an Inconelreactor vessel. The sodium was then stirred using a Cowles blade mixerrotating at 2000-2500 rpm. Powdered hafnium chloride (from Areva) waspulse-fed over approximately 1 hour into the stirred sodium, until 82 gof hafnium chloride had been added, at which point the reaction washalted. At the end of the reaction, the vortex in the sodium hadsubstantially disappeared and the reactor temperature had increased to301° C.

Once the reaction was completed, the reactor vessel was sealed,transferred to a furnace, and heated to 825° C. for four hours to reducethe surface area of the hafnium metal produced in the reaction. Duringthis process step, unreacted sodium was removed from the hafnium metalto leave a hafnium-sodium chloride composite.

The hafnium and sodium chloride mixture was then transferred to a vacuumfurnace and heated under vacuum to 2300° C., held at that temperaturefor one hour, and then cooled. This removed the sodium chloride andproduced a button of solid hafnium.

The hafnium button was analysed via glow discharge mass spectrometry(GDMS) and found to have 26 ppm oxygen content, 1690 ppm zirconium, andless than 150 ppm total transition metals. The results demonstrate theproduction of a low oxygen hafnium metal produced directly from hafniumpowder consolidation.

Example 7: Titanium-Aluminum

120 g of a 55% aluminum, 45% titanium powder (measured by metal content)was first prepared, by adding aluminum chloride powder (from StremChemical) to an aluminum-titanium chloride Ziegler Natta catalyst powder(also from Strem Chemical).

Next, 140 g of sodium metal was placed in an Inconel reactor and heatedto 250° C. Over approximately 2 hours, 94 g of the titanium-aluminumchloride powder mix was pulse fed into the sodium, which wascontinuously stirred by a Cowles blade mixer at between 1600 and 2500rpm. Powder addition continued until the mixer could no longer maintaina vortex in the sodium. At the end of the reaction the sodiumtemperature had increased to 292° C.

The Inconel reactor was then sealed, transferred to a furnace, andheated to 900° C. for 1 hour. After this step, the unreacted sodium wasremoved and the metal powder washed to remove its salt coating. Washingcontinued until the wash water conductivity fell below 2 microsiemens.Finally, the powder was dried in a vacuum over for 24 hours. Thetitanium-aluminum metal thus produced was found by ICPMS analysis tocontain below 100 ppm iron and below 150 ppm total transition metals.

Example 8: Titanium-Aluminum-Vanadium

First, 120 g of a titanium-aluminum-vanadium chloride mixture wasprepared, by mixing liquid titanium chloride (from Sigma Aldrich),aluminum chloride powder (from Strem Chemical) and liquid vanadiumchloride (from Acros Organics). The mixture was stirred constantly todissolve the aluminum trichloride into the titanium chloride andvanadium chloride liquid.

Next, 140 g of sodium metal was heated to 250° C. in an Inconel vesseland stirred by a Cowles blade mixer at speeds ranging from 1000 rpminitially, to 2500 rpm as the reaction progressed. The liquid chloridemixture was pumped into the reactor until 74 g had been added, overapproximately 90 minutes. The reaction stopped when the vortex in thesodium could no longer be maintained.

The reactor vessel was then sealed and transferred to a furnace, broughtto 825° C. and held at that temperature for approximately one hourbefore being allowed to cool.

The recovered product was then washed to remove the sodium chloridecoating the metal powder, and the powder was dried in a vacuum oven at100 C for 24 hours. The results demonstrate that the titanium powderfalls within the purity limits as described in UNS No. R56400.

Example 9: γ-Titanium-Aluminide (Ti 48Al2Nb 2Cr)

First, 200 g of a titanium-aluminum-niobium-chromium chloride mixturewas prepared, by mixing liquid titanium chloride (from Sigma Aldrich),sodium aluminum chloride powder (NaAlCl₄) (from Sigma-Aldrich), niobiumchloride (from Sigma Aldrich), and sodium chromium chloride powder(Na₃CrCl₅) (produced from NaCl and CrCl₂ both from Sigma Aldrich). Themixture was heated to 180° C. under 10 bar of pressure with constantstirring to maintain a well mixed liquid chloride feed.

Next, 5 kg of sodium metal was heated to 250° C. in an Inconel vesseland stirred by a Cowles blade mixer at speeds ranging from 1000 rpminitially, to 2500 rpm as the reaction progressed. The chloride mixturewas pumped into the reactor until 200 g had been added, overapproximately 90 minutes. The reaction stopped when the vortex in thesodium could no longer be maintained.

The reactor vessel was then sealed and transferred to a furnace, broughtto 825° C. and held at that temperature for approximately one hourbefore being allowed to cool.

The recovered product was then washed to remove the sodium chloridecoating the metal powder, and the powder was dried in a vacuum oven at100 C for 24 hours.

Analysis of the metal powder using ICPMS showed the product containedunder 50 ppm iron and under 150 ppm total transition metals differentfrom those used to make the alloy. From EDX analysis, theγ-titanium-aluminide composition fell within the specification of Al:32.4-33.6 wt % Cr: 2.4-2.8 wt % Nb: 4.5-5.1 wt %.

The present invention includes the followingaspects/embodiments/features in any order and/or in any combination:

-   1. A method for producing a metal powder, the method comprising:    -   a) combining at least one metal halide and at least one molten        reducing metal in a space that is substantially free of oxygen        and water, wherein said molten reducing metal is present in a        stoichiometric excess to the metal halide, to obtain a reaction        product that comprises at least one metal salt and metal, and        wherein the molten reducing metal comprises i) at least 90 wt %        sodium or potassium or a mixture of potassium and sodium or ii)        at least 90 wt % aluminum, magnesium, or titanium based on total        weight of said molten reducing metal, and the at least one metal        halide is a solid or liquid, with the proviso that the molten        reducing metal is different from the metal of the at least one        metal halide;    -   b) substantially removing unreacted said molten reducing metal        in said reaction product;    -   c) recovering at least said metal, wherein the metal of the        metal salt is the molten reducing metal, and the ‘metal’        recovered from the reaction product is from the metal of the        metal halide.-   2. The method of any preceding or following    embodiment/feature/aspect, wherein in step c), the at least one    metal salt is recovered with said metal.-   3. The method of any preceding or following    embodiment/feature/aspect, wherein said method further comprises d)    separating said metal from said metal salt.-   4. The method of any preceding or following    embodiment/feature/aspect, wherein two or more metal halides are    used and wherein said metal recovered comprises a metal alloy or    intermetallic compound from each metal of the two or more metal    halides.-   5. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide is    at least one metal chloride.-   6. A method for producing a metal masterbatch, the method    comprising:    -   a) combining at least one metal halide and at least one molten        reducing metal in a space that is substantially free of oxygen        and water, wherein said molten reducing metal is present in a        stoichiometric excess to the metal halide, to obtain a reaction        product that comprises at least one metal salt and metal, and        wherein the molten reducing metal comprises at least 90 wt %        aluminum, magnesium, or titanium based on total weight of said        molten reducing metal, and the at least one metal halide is a        solid or liquid, with the proviso that the molten reducing metal        is different from the metal of the at least one metal halide;    -   b) substantially removing said at least one metal salt to obtain        said metal masterbatch comprising at least a portion of said        molten reducing metal, and the metal, wherein the metal of the        metal salt is the molten reducing metal and the ‘metal’        recovered from the reaction product is from the metal of the        metal halide, wherein the removing of at least one metal salt        occurs during or after formation of said reaction product.-   7. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide    comprises Ti halide, V halide, Cr halide, Mn halide, Fe halide, Co    halide, Ni halide, Cu halide, Zn halide, Ga halide, Ge halide, As    halide, Se halide, Zr halide, Nb halide, Mo halide, Ru halide, Rh    halide, Pd halide, Ag halide, Cd halide, In halide, Sn halide, Sb    halide, C halide, Si halide, Te halide, Hf halide, Ta halide, W    halide, Hg halide, Tl halide, Pb halide, or Bi halide or any    combination thereof-   8. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide is    at least one metal chloride.-   9. The method of any preceding or following    embodiment/feature/aspect, wherein two or more metal halides are    used and wherein said metal recovered comprises a metal alloy,    intermetallic compound, or ceramic from each metal of the two or    more metal halides.-   10. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide is    at least one metal chloride.-   11. The method of any preceding or following    embodiment/feature/aspect, wherein said metal masterbatch comprises    aluminum, hafnium, and zirconium.-   12. The method of any preceding or following    embodiment/feature/aspect, further comprising adding a carbide,    nitride, or boride forming component to said metal halide or to said    molten reducing metal or both, and wherein said metal of the    reaction product comprises a metal carbide, a metal nitride, or a    metal boride or any combination thereof.-   13. The method of any preceding or following    embodiment/feature/aspect, wherein said carbide forming component    comprises carbon containing gas, carbon tetrachloride or solid    carbon.-   14. The method of any preceding or following    embodiment/feature/aspect, wherein said boride forming component    comprises boron trichloride or a boron hydride.-   15. The method of any preceding or following    embodiment/feature/aspect, wherein said substantially removing said    at least one metal salt comprises vaporization of said at least one    metal salt and removal thereof from said metal masterbatch.-   16. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide is    combined as a solid with said molten reducing metal.-   17. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide is    combined as a solid with a portion of said molten reducing metal to    form a mixture, and said portion of said molten reducing metal is at    a temperature that avoids reaction with said metal halide.-   18. The method of any preceding or following    embodiment/feature/aspect, said method further comprising combining    said mixture with part or all of the remaining portion of said    molten reducing metal that is at a temperature that permits reaction    with said metal halide.-   19. The method of any preceding or following    embodiment/feature/aspect, wherein said combined at least one metal    halide and at least one molten reducing metal passes through a    reaction zone that comprises at least one closed pipe that causes    turbulence in combined at least one metal halide and at least one    molten reducing metal and that optionally empties into a tank or    filter.-   20. The method of any preceding or following    embodiment/feature/aspect, wherein said molten reducing metal    comprises said at least 90 wt % sodium or potassium or a mixture of    potassium and sodium, and wherein combined at least one metal halide    and at least one molten reducing metal passes through a reaction    zone that empties into a settling tank that includes at least one    outlet that is located at a height in the settling tank that permits    said molten reducing metal from step b) to at least partly be    removed by said outlet but not said molten salt or said metal, and    wherein said combined at least one metal halide, at least one molten    reducing metal, and at least one metal salt together are at a    temperature that results in phase separation of the molten reducing    metal from said metal salt and said metal.-   21. The method of any preceding or following    embodiment/feature/aspect, wherein said combining said mixture with    part or all of the remaining portion of said molten reducing metal    that is at a temperature that permits reaction with said metal    halide comprises utilizing an eductor.-   22. The method of any preceding or following    embodiment/feature/aspect, prior to at least step b), wherein said    molten reducing metal comprises at least 90 wt % sodium or potassium    or a mixture of potassium and sodium, and wherein at least one metal    halide, at least one molten reducing metal and at least one metal    salt together are at a temperature that causes phase separation of    the molten reducing metal from said metal salt and said metal.-   23. The method of any preceding or following    embodiment/feature/aspect, wherein said substantially removing said    at least one metal salt comprises permitting the vaporization of at    least a portion of said at least one metal salt and removal thereof    from said metal masterbatch.-   24. The method of any preceding or following    embodiment/feature/aspect, wherein the at least one metal halide    comprises at least a first metal halide and a second metal halide,    with the first metal halide reactive with the metal salt and the    second metal halide non-reactive with the metal salt, wherein the    metal of the second metal halide is the same or different from the    molten reducing metal.-   25. The method of any preceding or following    embodiment/feature/aspect, wherein the second metal halide is NaCl    and the molten reducing metal is said at least 90 wt % sodium, and    the first metal halide is AlCl₃.-   26. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide    comprises a halide of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As,    Se, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Hf, Ta, W, Hg,    Tl, Pb, or Bi or any combination thereof.-   27. The method of any preceding or following    embodiment/feature/aspect, wherein said first metal halide and said    second metal halide form a eutectic mixture.-   28. The method of any preceding or following    embodiment/feature/aspect, wherein said at least one metal halide is    two or more metal halides, and one metal halide is a solid or liquid    and the other metal halide is a vapor, solid, or liquid.-   29. The method of any preceding or following    embodiment/feature/aspect, wherein said at one least metal halide is    three or more metal halides, and one metal halide is a solid or    liquid and the other metal halides are a vapor, solid, or liquid.-   30. The method of any preceding or following    embodiment/feature/aspect, wherein said metal salt at least    partially coats or encapsulates said metal.-   31. The method of any preceding or following    embodiment/feature/aspect, wherein said molten reducing metal is    aluminum alloy.-   32. The method of any preceding or following    embodiment/feature/aspect, wherein said molten reducing metal is    magnesium alloy.-   33. The method of any preceding or following    embodiment/feature/aspect, wherein said molten reducing metal is    titanium alloy.

The present invention can include any combination of these variousfeatures or embodiments above and/or below as set forth in sentencesand/or paragraphs. Any combination of disclosed features herein isconsidered part of the present invention and no limitation is intendedwith respect to combinable features.

Applicant specifically incorporates the entire contents of all citedreferences in this disclosure. Further, when an amount, concentration,or other value or parameter is given as either a range, preferred range,or a list of upper preferable values and lower preferable values, thisis to be understood as specifically disclosing all ranges formed fromany pair of any upper range limit or preferred value and any lower rangelimit or preferred value, regardless of whether ranges are separatelydisclosed. Where a range of numerical values is recited herein, unlessotherwise stated, the range is intended to include the endpointsthereof, and all integers and fractions within the range. It is notintended that the scope of the invention be limited to the specificvalues recited when defining a range.

Other embodiments of the present invention will be apparent to thoseskilled in the art from consideration of the present specification andpractice of the present invention disclosed herein. It is intended thatthe present specification and examples be considered as exemplary onlywith a true scope and spirit of the invention being indicated by thefollowing claims and equivalents thereof

What is claimed is:
 1. A method for producing a metal powder, the methodcomprising: a) combining at least one metal halide and at least onemolten reducing metal in a space that is substantially free of oxygenand water, wherein said molten reducing metal is present in astoichiometric excess to the metal halide, to obtain a reaction productthat comprises at least one metal salt and metal, and wherein the moltenreducing metal comprises i) at least 90 wt % sodium or potassium or amixture of potassium and sodium or ii) at least 90 wt % aluminum,magnesium, or titanium based on total weight of said molten reducingmetal, and the at least one metal halide is a solid or liquid, with theproviso that the molten reducing metal is different from the metal ofthe at least one metal halide; b) substantially removing unreacted saidmolten reducing metal in said reaction product; c) recovering at leastsaid metal, wherein the metal of the metal salt is the molten reducingmetal, and the ‘metal’ recovered from the reaction product is from themetal of the metal halide.
 2. The method of claim 1, wherein in step c),the at least one metal salt is recovered with said metal.
 3. The methodof claim 2, wherein said method further comprises d) separating saidmetal from said metal salt.
 4. The method of claim 1, wherein two ormore metal halides are used and wherein said metal recovered comprises ametal alloy or intermetallic compound from each metal of the two or moremetal halides.
 5. The method of claim 1, wherein said at least one metalhalide is at least one metal chloride.
 6. A method for producing a metalmasterbatch, the method comprising: a) combining at least one metalhalide and at least one molten reducing metal in a space that issubstantially free of oxygen and water, wherein said molten reducingmetal is present in a stoichiometric excess to the metal halide, toobtain a reaction product that comprises at least one metal salt andmetal, and wherein the molten reducing metal comprises at least 90 wt %aluminum, magnesium, or titanium based on total weight of said moltenreducing metal, and the at least one metal halide is a solid or liquid,with the proviso that the molten reducing metal is different from themetal of the at least one metal halide; b) substantially removing saidat least one metal salt to obtain said metal masterbatch comprising atleast a portion of said molten reducing metal and the metal, wherein themetal of the metal salt is the molten reducing metal, and the ‘metal’recovered from the reaction product is from the metal of the metalhalide, wherein the removing of at least one metal salt occurs during orafter formation of said reaction product.
 7. The method of claim 1,wherein said at least one metal halide comprises Ti halide, V halide, Crhalide, Mn halide, Fe halide, Co halide, Ni halide, Cu halide, Znhalide, Ga halide, Ge halide, As halide, Se halide, Zr halide, Nbhalide, Mo halide, Ru halide, Rh halide, Pd halide, Ag halide, Cdhalide, In halide, Sn halide, Sb halide, C halide, Si halide, Te halide,Hf halide, Ta halide, W halide, Hg halide, Tl halide, Pb halide, or Bihalide or any combination thereof.
 8. The method of claim 6, whereinsaid at least one metal halide is at least one metal chloride.
 9. Themethod of claim 6, wherein two or more metal halides are used andwherein said metal recovered comprises a metal alloy, intermetalliccompound, or ceramic from each metal of the two or more metal halides.10. The method of claim 1, wherein said at least one metal halide is atleast one metal chloride.
 11. The method of claim 6, wherein said metalmasterbatch comprises aluminum, hafnium, and zirconium.
 12. The methodof claim 6, further comprising adding a carbide, nitride, or borideforming component to said metal halide or to said molten reducing metalor both, and wherein said metal of the reaction product comprises ametal carbide, a metal nitride, or a metal boride or any combinationthereof.
 13. The method of claim 12, wherein said carbide formingcomponent comprises carbon containing gas, carbon tetrachloride or solidcarbon.
 14. The method of claim 12, wherein said boride formingcomponent comprises boron trichloride or a boron hydride.
 15. The methodof claim 6, wherein said substantially removing said at least one metalsalt comprises vaporization of said at least one metal salt and removalthereof from said metal masterbatch.
 16. The method of claim 1, whereinsaid at least one metal halide is combined as a solid with said moltenreducing metal.
 17. The method of claim 16, wherein said at least onemetal halide is combined as a solid with a portion of said moltenreducing metal to form a mixture, and said portion of said moltenreducing metal is at a temperature that avoids reaction with said metalhalide.
 18. The method of claim 17, said method further comprisingcombining said mixture with part or all of the remaining portion of saidmolten reducing metal that is at a temperature that permits reactionwith said metal halide.
 19. The method of claim 1, wherein said combinedat least one metal halide and at least one molten reducing metal passesthrough a reaction zone that comprises at least one closed pipe thatcauses turbulence in combined at least one metal halide and at least onemolten reducing metal and that optionally empties into a tank or filter.20. The method of claim 1, wherein said molten reducing metal comprisessaid at least 90 wt % sodium or potassium or a mixture of potassium andsodium, and wherein combined at least one metal halide and at least onemolten reducing metal passes through a reaction zone that empties into asettling tank that includes at least one outlet that is located at aheight in the settling tank that permits said molten reducing metal fromstep b) to at least partly be removed by said outlet but not said moltensalt or said metal, and wherein said combined at least one metal halide,at least one molten reducing metal, and at least one metal salt togetherare at a temperature that results in phase separation of the moltenreducing metal from said metal salt and said metal.
 21. The method ofclaim 18, wherein said combining said mixture with part or all of theremaining portion of said molten reducing metal that is at a temperaturethat permits reaction with said metal halide comprises utilizing aneductor.
 22. The method of claim 1, prior to at least step b), whereinsaid molten reducing metal comprises at least 90 wt % sodium orpotassium or a mixture of potassium and sodium, and wherein at least onemetal halide, at least one molten reducing metal and at least one metalsalt together are at a temperature that causes phase separation of themolten reducing metal from said metal salt and said metal.
 23. Themethod of claim 1, wherein said substantially removing said at least onemetal salt comprises permitting the vaporization of at least a portionof said at least one metal salt and removal thereof from said metalmasterbatch.
 24. The method of claim 1, wherein the at least one metalhalide comprises at least a first metal halide and a second metalhalide, with the first metal halide reactive with the metal salt and thesecond metal halide non-reactive with the metal salt, wherein the metalof the second metal halide is the same or different from the moltenreducing metal.
 25. The method of claim 6, wherein the at least onemetal halide comprises at least a first metal halide and a second metalhalide, with the first metal halide reactive with the metal salt and thesecond metal halide non-reactive with the metal salt, wherein the metalof the second metal halide is the same or different from the moltenreducing metal.
 26. The method of claim 24, wherein the second metalhalide is NaCl and the molten reducing metal is said at least 90 wt %sodium, and the first metal halide is AlCl₃.
 27. The method of claim 25,wherein the second metal halide is NaCl and the molten reducing metal issaid at least 90 wt % sodium, and the first metal halide is AlCl₃. 28.The method of claim 6, wherein said at least one metal halide comprisesTi halide, V halide, Cr halide, Mn halide, Fe halide, Co halide, Nihalide, Cu halide, Zn halide, Ga halide, Ge halide, As halide, Sehalide, Zr halide, Nb halide, Mo halide, Ru halide, Rh halide, Pdhalide, Ag halide, Cd halide, In halide, C halide, Si halide, Sn halide,Sb halide, Te halide, Hf halide, Ta halide, W halide, Hg halide, Tlhalide, Pb halide, or Bi halide or any combination thereof.
 29. Themethod of claim 24, wherein said first metal halide and said secondmetal halide form a eutectic mixture.
 30. The method of claim 1, whereinsaid at least one metal halide is two or more metal halides, and onemetal halide is a solid or liquid and the other metal halide is a vapor,solid, or liquid.
 31. The method of claim 6, wherein said at one leastmetal halide is two or more metal halides, and one metal halide is asolid or liquid and the other metal halide is a vapor, solid, or liquid.32. The method of claim 1, wherein said metal salt at least partiallycoats or encapsulates said metal.
 33. The method of claim 1, whereinsaid molten reducing metal is aluminum alloy.
 34. The method of claim 1,wherein said molten reducing metal is magnesium alloy.
 35. The method ofclaim 1, wherein said molten reducing metal is titanium alloy.
 36. Themethod of claim 6, wherein said molten reducing metal is aluminum alloy.37. The method of claim 6, wherein said molten reducing metal ismagnesium alloy.
 38. The method of claim 6, wherein said molten reducingmetal is titanium alloy.